From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E90ACC433F5 for ; Fri, 10 Sep 2021 23:40:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B74C661215 for ; Fri, 10 Sep 2021 23:40:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234835AbhIJXmF (ORCPT ); Fri, 10 Sep 2021 19:42:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40456 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232762AbhIJXmD (ORCPT ); Fri, 10 Sep 2021 19:42:03 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EE3CFC061574 for ; Fri, 10 Sep 2021 16:40:51 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id j4-20020a258b84000000b005a203c5e066so4527459ybl.19 for ; Fri, 10 Sep 2021 16:40:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:message-id:mime-version:subject:from:to:cc; bh=dYKLTLpTmPN5owZVdEoA+CQx6wna9pjFHY01/pfiuQ4=; b=qbSqVK6szk9xdAsM43A6koMNq4VP1LjnW0p3/8Vt9yRFopGXZYEnh4nMRg/L/3wcVr vhf54uss1p4pRCskahb0hYnFAA884g6S2mh/+X2kWxE7qoBdKbnSrHFTPV5+rPKUHXx3 Uywymn8mfLubGmT1bbAR0HILPB8WzNzL9PMTR1uRWFN/oJbXuqZAVkEI0jbYODZumaC+ rP7zF26TLmTid/DG6mfWJa19+zM5RsgHwyXMfeiQSsCZXumWVFpGeO3Tdk7DCslN3Py4 n4kXcTGIacTVlJiZCu6mzP+7UpecLXplK6MSWj1JySzZ+MI5WKuO0Nh8gJuptedkPY52 TGUA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=dYKLTLpTmPN5owZVdEoA+CQx6wna9pjFHY01/pfiuQ4=; b=ne9S6AqXmpwv0BzV5ZwAjHkVKWmksfRfrn5Yrpgf8UfGZwZn2V9ip/aCrnwyLesPYd h1yH7zHNOt5BjYK4zibGSWenFHKru93xeLcveya5WEbtQfRzDWd6hMbMdwjxHEiM7uRR ySWPLEfotyYrxXqm1k7+efvuNvHqhZ8si0yDGmGF+30kVNAA7dugtulpbAjQnXk4cL4H j0qYqhbm7xl4HmziMqC10fTqEGKYPoMFOijF70jD2HjHJeSDpzVxwdltuh/m+Dl2tvdW 4zIcFy9+szMlgWTXHQ+mYyxios3mokgLKzQcVYrRN6uyGpe+Cb8ByupYsFSlpefipMR5 c6jA== X-Gm-Message-State: AOAM532BMy+bR4EaOcHFaSh+Vb0lOnHrQ18dWAzl2k57tELkL7mFHhgx lAbDJI+6z0sEREK1L5vpNLnQU45lb8Ev5FIxBGY= X-Google-Smtp-Source: ABdhPJyUCPirWrWj7upjL/zaVjTC/3QtOA7QWlPN2tum9NX/Ts98LvdkJJzWo4804NqGsqkXClfYxb0whU0Qm7r6prg= X-Received: from ndesaulniers1.mtv.corp.google.com ([2620:15c:211:202:2b76:71d3:b5fb:3734]) (user=ndesaulniers job=sendgmr) by 2002:a25:a527:: with SMTP id h36mr404031ybi.104.1631317251104; Fri, 10 Sep 2021 16:40:51 -0700 (PDT) Date: Fri, 10 Sep 2021 16:40:37 -0700 Message-Id: <20210910234047.1019925-1-ndesaulniers@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.33.0.309.g3052b89438-goog Subject: [PATCH 00/10] raise minimum GCC version to 5.1 From: Nick Desaulniers To: Andrew Morton Cc: Linus Torvalds , Rasmus Villemoes , Nathan Chancellor , Masahiro Yamada , Joe Perches , Arnd Bergmann , Stephen Rothwell , llvm@lists.linux.dev, linux-kernel@vger.kernel.org, Nick Desaulniers Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org commit fad7cd3310db ("nbd: add the check to prevent overflow in __nbd_ioctl()") raised an issue from the fallback helpers added in commit f0907827a8a9 ("compiler.h: enable builtin overflow checkers and add fallback code") Specifically, the helpers for checking whether the results of a multiplication overflowed (__unsigned_mul_overflow, __signed_add_overflow) use the division operator when !COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW. This is problematic for 64b operands on 32b hosts. Also, because the macro is type agnostic, it is very difficult to write a similarly type generic macro that dispatches to one of: * div64_s64 * div64_u64 * div_s64 * div_u64 Raising the minimum supported versions allows us to remove all of the fallback helpers for !COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW, instead dispatching the compiler builtins. arm64 has already raised the minimum supported GCC version to 5.1, do this for all targets now. See the link below for the previous discussion. Additional patches cleaning up a few obsolete version checks. Link: https://lore.kernel.org/all/20210909182525.372ee687@canb.auug.org.au/ Link: https://lore.kernel.org/lkml/CAK7LNASs6dvU6D3jL2GG3jW58fXfaj6VNOe55NJnTB8UPuk2pA@mail.gmail.com/ Link: https://github.com/ClangBuiltLinux/linux/issues/1438 Nick Desaulniers (10): Documentation: raise minimum supported version of GCC to 5.1 compiler.h: drop fallback overflow checkers mm/ksm: remove old GCC 4.9+ check Kconfig.debug: drop GCC 5+ version check for DWARF5 riscv: remove Kconfig check for GCC version for ARCH_RV64I powerpc: remove GCC version check for UPD_CONSTR arm64: remove GCC version check for ARCH_SUPPORTS_INT128 Makefile: drop GCC < 5 -fno-var-tracking-assignments workaround compiler-gcc.h: drop checks for older GCC versions vmlinux.lds.h: remove old check for GCC 4.9 Documentation/process/changes.rst | 2 +- Makefile | 6 -- arch/arm64/Kconfig | 2 +- arch/powerpc/include/asm/asm-const.h | 10 -- arch/riscv/Kconfig | 2 +- include/asm-generic/vmlinux.lds.h | 4 - include/linux/compiler-clang.h | 13 --- include/linux/compiler-gcc.h | 8 +- include/linux/overflow.h | 138 +------------------------- lib/Kconfig.debug | 2 +- mm/ksm.c | 2 - scripts/min-tool-version.sh | 8 +- tools/include/linux/compiler-gcc.h | 8 +- tools/include/linux/overflow.h | 140 +-------------------------- 14 files changed, 13 insertions(+), 332 deletions(-) base-commit: 2d338201d5311bcd79d42f66df4cecbcbc5f4f2c -- 2.33.0.309.g3052b89438-goog